Fenestrated swivel anchor for knotless fixation of tissue

ABSTRACT

A method and device for knotless fixation of tissue. A swivel anchor having a rotatable implant is used to capture suture for surgical tissue repair without requiring suture knots. The implant may be provided with a conical metal tip which is self-punching and avoids the need for pre-drilling a hole in bone. The implant includes a closed aperture to allow free sliding of a suture strand. The swivel anchor is secured in a hole in bone by advancing a fenestrated fixation device, such as a cannulated interference screw, over the body of the implant.

This application is a continuation-in-part of application Ser. No.12/368,946, filed on Feb. 10, 2009, which is a CIP of application Ser.No. 12/043,008, filed on Mar. 5, 2008, which in turn is acontinuation-in-part of application Ser. No. 11/802,057, filed on May18, 2007, which claims the benefit of Provisional Application Ser. No.60/801,097, filed on May 18, 2006, the entire disclosures of which areincorporated herein by reference.

FIELD OF THE INVENTION

The present invention relates to methods and instruments for fixation ofsutures and tissue to bone.

BACKGROUND OF THE INVENTION

When soft tissue tears away from bone, reattachment becomes necessary.Various devices, including sutures, screws, staples, wedges, anchors andplugs have been used in the prior art to secure soft tissue to bone.Surgical methods utilizing suture anchors alone are disadvantageous forreattachment of large areas of detached tissue because they often do notallow good tissue to bone contact.

Reattachment of soft tissue to bone typically requires the surgeon topass suture material through selected tissue, form a plurality ofsurgical knots extracorporeally and then move the knots into positionadjacent the desired tissue to be sutured. In such procedures, thesurgeon must manually tie the knots on the suture strands after thesuture is threaded through the selected tissues to be sutured. Knottying during surgery, particularly arthroscopic surgery, is tedious andtime-consuming. There is also a tendency for the knots to deform orcollapse as the surgeon manually forces the knots down into the properposition. Also, the suture knots often are exposed to abrasion orcutting by sharp or rough areas along the walls of the bone canal intowhich anchors are typically inserted to provide fixation of tendon tobone.

Accordingly, a need exists for an improved method for attaching softtissue to bone which does not require multiple suture knots and whichallows the tendon to remain securely in place until the ligamentsnaturally attach to bone. A need also exists for such a knotless methodof attaching tissue to bone which employs an implant with a fenestratedconfiguration that promotes healing of tissue.

SUMMARY OF THE INVENTION

The instruments and methods of the present invention overcome thedisadvantages of the prior art, such as those noted above, by providinga swivel implant at the distal end of a driver that securely engages andlocks into a cannulated ribbed body of an interference plug or screw.The swivel implant includes a closed aperture for receiving a strandattached to a graft, such that the strand is able to freely slidethrough the aperture.

In one embodiment of the invention, the strand is passed through thegraft at desired points. A cannulated plug or screw is pre-loaded onto adriver provided with a swivel lock twist-in anchor at its distal end.The strand attached to the graft is passed through the aperture of theswivel implant located at the distal end of the driver. The distal endof the driver together with the implant is inserted directly into thebone. The driver may be rotated (in a clockwise direction, for example)to advance a screw over the anchor to complete insertion. The cannulatedplug or screw is provided with a plurality of openings or fenestrationsof various dimensions and geometries to provide multiple pathwaysthrough the device (i.e., though the interior of the body and throughthe fenestrations) to allow blood to flow to increase the healing zone,for example, for rotator cuff repair, while also promoting bonein-growth.

Other features and advantages of the present invention will becomeapparent from the following description of exemplary embodiments of theinvention described with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1-6 depict a series of steps of shoulder repair using a pluralityof swivel anchor devices according to the present invention.

FIG. 7 illustrates various views of the driver assembly of the presentinvention.

FIGS. 8 and 9 illustrate the swivel implant and traction suture.

FIG. 10 is an enlarged view of the fixation device (cannulated screw)used in the present invention.

FIG. 11 illustrates various views of a swivel anchor with a metal tipwhich avoids the need to pre-drill a hole in bone.

FIGS. 12 and 13 provide additional illustrations of the swivel anchorassembly of the present invention, and the swivel anchor inserted in abone socket, respectively.

FIGS. 14-16 illustrate various views of a fixation device withfenestrations and used in conjunction with the swivel anchor assembly ofthe present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention provides apparatus and methods for knotless tissuefixation using a swivel anchor device.

FIG. 1 illustrates a side view of a human shoulder of a patientundergoing a rotator cuff repair in accordance with an exemplaryembodiment of the present invention. The patient may be positioned inthe beach chair position using the Arthrex Beach Chair Lateral TractionDevice or in a lateral decubitus position using the Arthrex 3-PointShoulder Distraction System. Access to the subacromial space isfacilitated with a variety of cannulas.

First, and as illustrated in FIG. 1, the mobility of the tear isassessed using, for example, a tissue grasper 10 such as the ArthrexKingFisher™ Suture Retriever/Tissue Grasper, to determine whether a U orL-shaped component exists. Where large tears extend to the superioraspect of the glenoid, margin convergence suturing is performed toreduce volume and strain on the repair. Subsequently, the length andwidth of the rotator cuff footprint is assessed and a bleeding bed forenhanced tendon to bone healing may be formed. This may be accomplishedwith a burr to perform a light dusting of the greater tuberosity, or byusing a chondro pick to microfracture the footprint and maximizevascular channels.

FIG. 2 illustrates the preparation of two pilot holes for two swivelanchors that will be inserted in the medial row. A punch may be employedadjacent to the articular margin of the humerus and at about 45° angleto form the two pilot holes.

Subsequent to the formation of the pilot holes, and as shown in FIGS. 3and 4, a swivel implant 30, loaded with a strand of suture tape 40,preferably Arthrex FiberTape, is placed in the medial pre-formed hole32. Arthrex FiberTape is a high strength suture tape which is braidedand rectangular-like in cross section and is disclosed in U.S. PatentApplication Publication No. 2005/0192631, the disclosure of which isincorporated by reference herein. However, the anchor of the presentinvention can be used with any type of flexible material or suture. Thedriver is then rotated to advance screw 42 down shaft 20 to secure theimplant and suture in the bone hole. More specifically, as shown in FIG.4 a, the screw 42 is advanced by holding thumb pad 50 as the driverhandle 22 is turned clockwise. An Arthrex FiberLink and an ArthrexScorpion suture passer 44, are used to shuttle both tails of the suturetape through the rotator cuff 34 simultaneously. This procedure isfollowed for both medial swivel anchors.

Referring to FIG. 5, one tail of suture tape 40 from each medial swivelanchor is retrieved and loaded through the eyelet of another swivelimplant 30, and that implant is installed in then inserted into apreformed lateral bone socket. The tension of the suture tape 40 isadjusted if necessary. The swivel anchor driver is then rotated inclockwise direction as before to advance the screw 42 over the implantto complete insertion. This step is repeated in another lateral bonesocket with the other tails of suture tape from each medial anchor. Thetails of the suture tape 40 are then cut, one at a time, to complete theconstruct as shown in FIG. 6. The method is analogous to the methoddisclosed in U.S. Patent Application Publication No. 2007/0191849, theentire disclosure of which is incorporated by reference herein. FIGS. 12and 13 provide additional illustrations of the swivel anchor assemblyand the anchor inserted in a bone socket, respectively.

The swivel anchor and instruments of the present invention are nowdescribed in greater detail. As shown in FIGS. 7( a)-(f), a driver 68 isused to install the knotless fixation devices with a swiveling implant.Driver 68 features a thin cannulated rod 20 passing slidably androtatably through a cannulated driver assembly. The tip of thincannulated rod 20 is adapted to accept swivel anchor implant 42 withinthe cannulation at its tip, preferably via a snap fit. Cannulated rod 20has a hexagonal outer surface for receiving anchor body (preferably ascrew) 42 having a corresponding cannulation. FIG. 10 illustrates adetailed view of the cannulated screw 42.

During installation of the knotless anchor having a swiveling implant30, the screw 42 is first inserted onto cannulated rod 20 of the driver68. As shown in FIGS. 7( a) and (b), screw 42 is loaded onto rod 20 andthen fully seated on the shaft end of the driver. FIG. 7( c) illustratesthe swivel anchor implant 30. As shown in FIGS. 8-9, traction sutures 71extending from the proximal end of the swivel anchor implant 30 arethreaded through the cannulation of the driver 68 (see also FIG. 7( c)).These traction sutures 71 prevent inadvertent separation of the implant30 from the driver during insertion, but they can be used subsequentlyfor additional tie-down of the tendon after the driver is removed.Subsequently, the swivel anchor implant 30 is seated on the driver tipand until advanced until it snaps onto place (FIG. 7( d)). A protectivetube 94 (FIG. 7( e)) may be placed over the tip of the assembly forshipping purposes. The traction sutures 71 may be looped around thedriver handle, as shown in FIGS. 7( f) and (g), and secured in a cleat98 to prevent the implant 200 from becoming prematurely detached fromthe driver.

The knotless fixation device of the present invention advantageouslyminimizes or eliminates the need to tie knots. The use of such a swivelanchor also provides secure fixation of the suture construct—the securesuture construct results from the suture being pushed into a hole andheld tightly by an anchors.

In the preferred embodiment of the present invention, as mentionedabove, suture tape is used with the swivel anchor to fix tissue to bone.However, the swivel anchor of the present invention can be used with anytype of flexible material or suture. In another preferred embodiment, anallograft or biological component may be used instead of suture or tape.The allograft or biological component may be comprised of tendon orpericardium, for example, which provides improved tissue repair. In yetadditional embodiments, any combination of suture, suture tape, andallograft or biological component may be employed, depending on thecharacteristics of the specific surgical repair and/or as desired.

FIG. 11 illustrate a swivel implant 500 which is provided with a pointedmetal tip to facilitate insertion of the implant without the need topre-drill or pre-form a hole in the bone. The conical configuration ofthe most distal end pointed tip 550 allows the implant to undergo aself-punching operation, eliminating any need to pre-drill a hole in thebone. The conical configuration of the most distal end of the pointedtip implant 550 also provides suture fixation strength, as well asaccelerated graft/tendon healing to bone. The pointed tip implant 550may be detachable from the driver.

As illustrated in FIGS. 11( a)-(e), pointed tip implant 500 is providedwith a metal tip 550 and an eyelet or aperture 555 for receiving sutureor suture tape. Pointed tip implant 550 is also provided, at its mostdistal end, with a conical portion 551 which allows direct advancementof the implant (by simply tapping the device with a mallet, for example)without the formation of a pilot hole in bone. Preferably, the conicalportion 551 of the implant is formed of titanium or titanium alloy. In apreferred embodiment, eyelet or aperture 555 is also formed of titaniumor similar material, to withstand impaction forces during the graftfixation procedure.

FIGS. 14-16 illustrate various views of another exemplary fixationdevice 600 of the present invention that is employed in conjunction withthe driver assembly 68 and a swivel anchor or implant of the presentinvention (such as the swivel anchor implant 30 or the swivel implant500 described above). The fixation device 600 is similar to the fixationdevice (swivel anchor implant) 42 of FIG. 10, but differs from it inthat the fixation device 600 is provided with a plurality of openings orfenestrations 605 provided on the outer surface of the body of thedevice. The openings or fenestrations 605 may have various dimensionsand geometries provide multiple pathways for w blood to pass through thedevice (i.e, through the fenestrations and up through the cannulation)and, therefore, to the repair site to promote healing. The fenestrationsalso promote in-growth of bone. The decreased mass of the device 600(resulting from the fenestrations) further promotes healing andin-growth.

Preferably, the fixation device 600 is preloaded on the driver 68. Asdescribed above with reference to the three exemplary embodiments, thefixation device 600 is advanced into the bone socket by holding thethumb pad 50 as the driver handle 22 is turned clockwise. When thefixation device 600 is fully seated, the shaft of the anchor implant 30or the swivel implant 500 is fully engaged by the fixation device 600 tooptimize the stability of the swivel anchor construct (composed ofswivel anchor or implant 30, 500 and fixation device 600).

As illustrated in FIGS. 14-16, the fixation device 600 includes acannulated body 612 in the form of a tapered cylinder having a proximalend 613 and a distal end 615. A continuous thread 620 wraps aroundcannulated body 612 in a clockwise direction, as shown. As shown in FIG.15, the distal end 615 of the interference screw 600 terminates in anexposed, flat surface provided with an opening 616. The proximal end 613of the interference screw 600 terminates in a drive socket 617 thatallows a driver to seat snuggly in the drive socket to allowmanipulation and installation of the interference screw into the bonesocket, while fully engaging the shaft of the swivel anchor 30 or swivelimplant 500 (as detailed above with reference to interference screw 42).As shown in FIG. 16, drive socket 617 may be configured to be used witha traditional hex drive screwdriver. Although the drive socket 617 hasbeen described as having hexagonal shape, the drive socket may also havea Delta drive configuration or a cruciform shape, among others, thatallows the driver to rotationally engage the interference screw, to turnsimultaneously with the driver.

The fixation device 600 of the present invention may be formed of abiocompatible and/or biosorbable material. Preferably, screw 600 isformed of a bioabsorbable material, such as poly-(L-lactic acid) (PLLA),poly-(D,L-lactide), and poly glycolic acid (PGA), for example, or otherbioabsorbable, non-metallic materials, which may be especially tailoredfor hardness, tensile strength and compressive strength. Alternatively,fixation device 600 may be formed of titanium, titanium alloy, stainlesssteel or stainless steel alloy. Other biocompatible materials whichcould be used include plastics, allograft bone and inert bone substitutematerials.

A growth material may be advanced through the cannulated driver and intothe screw 600 by employing a plunger, for example. As the driver ispulled out, the plunger pushes the flow material through the cannulationof the driver and into the body of the screw 600. The growth materialwill subsequently harden to allow better fixation of the interferencescrew 600 against the bone and the shaft of the swivel anchor 30 orswivel implant 500.

The growth material may be any solid, semi-solid, viscous, flowable, gelor elastic composition or mixture that allows its easy manipulation andinsertion into the body 612 of the interference screw 600. The growthmaterial may contain growth factors such as autogenous growth factors,for example platelet-rich plasma (PRP), optionally in combination withhyaluronic acid (HY acid) and/or with a coagulant such as thrombin.

The term “growth factor” as used in the present application is intendedto include all factors, such as proteinaceous factors, for example,which play a role in the induction or conduction of growth of bone,ligaments, cartilage or other tissues associated with bone or joints. Inparticular, these growth factors include bFGF, aFGF, EGF (epidermalgrowth factor), PDGF (platelet-derived growth factor), IGF (insulin-likegrowth factor), TGF-β. I through III, including the TGF-β. superfamily(BMP-1 through 12, GDF 1 through 12, dpp, 60A, BIP, OF).

Optionally, the growth material may comprise additional osteoconductivebone adhesives, calcium carbonate, fatty acids, lubricants, antisepticchemicals and/or antibiotics. In this case, other solution excipientssuch as buffer salts, sugars, anti-oxidants and preservatives tomaintain the bioactivity of the growth material and a proper pH of thegrowth material may be also employed. The additional lubricants and/orthe antiseptic and/or the antibiotic will typically be present in thegrowth material in a predetermined concentration range, which will bedependent upon the particular bone site and application, as well as thespecific activity of the antiseptic and/or the antibiotic.

Although the present invention has been described in relation toparticular embodiments thereof, many other variations and modificationsand other uses will become apparent to those skilled in the art. It ispreferred, therefore, that the present invention be limited not by thespecific disclosure herein.

1. A method of tissue fixation comprising: providing a suture; securingthe suture to the tissue to be fixated; and anchoring the suture intothe bone socket using a swivel implant and a fixation device providedwith side fenestrations, thereby providing tissue fixation.
 2. Themethod of claim 1, wherein the fixation device is an cannulatedinterference screw or a cannulated plug.
 3. The method of claim 1,wherein the swivel implant has a conical portion terminating at apointed tip at its most distal end.
 4. The method of claim 1, whereinthe swivel implant has a closed aperture at its distal end.
 5. Themethod of claim 1, further comprising the step of capturing the sutureattached to the graft with the swivel implant.
 6. The method of claim 5,wherein the step of capturing the suture further comprises passing thesuture through a closed aperture of the swivel implant.
 7. The method ofclaim 6, wherein the closed aperture has an eyelet configuration.
 8. Themethod of claim 1, further comprising the steps of preloading thefixation device on a driver and, subsequently, providing the swivelimplant at a distal end of the driver.
 9. A suture anchor comprising: ananchor body provided with side fenestrations; and an anchor tiprotatably attached to the anchor body.
 10. The suture anchor of claim 9,wherein the anchor tip has a closed aperture.
 11. The suture anchor ofclaim 9, wherein the anchor tip is a metal tip.
 12. The suture anchor ofclaim 9, wherein the suture anchor is configured to allow rotationalinsertion without causing excessive twisting and knotting of a suturecaptured in the anchor tip.
 13. The suture anchor of claim 9, whereinthe anchor tip is configured to capture a suture.
 14. The suture anchorof claim 9, wherein the anchor body has a cylindrical configuration. 15.The suture anchor of claim 9, wherein the anchor tip is detachable. 16.The suture anchor of claim 9, further comprising a fixation device forsecuring the suture anchor in bone.
 17. The suture anchor of claim 16,wherein the fixation device is a cannulated interference screw or aplug.
 18. The suture anchor of claim 17, wherein the fixation device isa cannulated device.